Intrathecal administration (IT) is a route of administration for drugs via an injection into the spinal canal, or into the subarachnoid space so that it reaches the cerebrospinal fluid (CSF). Traditionally, the IT route of administration has been used to bypass the blood brain barrier (BBB).
Drugs may be administered by standard routes (IV, Oral) with CSF collection to assess CNS drug exposure and biomarker levels.